A composition comprises in an aqueous dispersion phase, a dispersion of lipid vesicles that encapsulate an aqueous phase. The lipid vesicles are a lipid phase containing an ionic amphiphilic lipid or a nonionic amphiphilic lipid, or a mixture thereof, together with a compound having the formula ##STR1## represents --CH.sub.2 OH, --COOM or --(CH.sub.2).sub.2 --COOM, wherein M represents H, alkali metal or alkaline earth metal and X, Y, Z and V, each independently, represent hydrogen or hydroxyl, with the proviso that when W represents --CH.sub.2 OH at least one of X, Y, Z or V represents hydroxyl, or (b) W represents --CH.sub.3 and X, Y, Z and V represent H or OH combined as shown in each line of the table below:

Claim:

We claim:

1. A composition comprising, in an aqueous dispersion phase, a dispersion of lipid vesicles encapsulating an aqueous phase, said lipid vesicles comprising a lipid phase containing acompound selected from the group consisting of phytanetriol,

5,9,13,17-tetramethyloctadecanoic acid,

3,7,11,15-tetramethyl-1,2,3,4-tetrahydrohexadecane and

3-hydroxymethyl-7,11,15-trimethyl-1,2,4-trihydroxyhexadecane,

together with (a) an ionic amphiphilic lipid or (b) a nonionic amphiphilic lipid, or a mixture of (a) and (b).

2. The composition of claim 1 wherein said compound of formula (I) represents from 5% to 90% by weight of said lipid vesicles.

3. The composition of claim 1 wherein the lipid of said vesicles is a nonionic amphiphilic lipid selected from the group consisting of

(4) a fatty oxyethylenated alcohol, a fatty non-oxyethylenated alcohol, an oxyethylenated phytosterol, a non-oxyethylenated phytosterol, an oxyethylenated sterol or a non-oxyethylenated sterol;

(5) an oxyethylenated ether of a polyol, a non-oxyethylenated ether of a polyol, an oxyethylenated ester of a polyol or a non-oxyethylenated ester of a polyol, wherein the ethylene oxide chain is linear or cyclic;

(6) a natural or synthetic glycolipid, an ether or ester of a mono- or polysaccharide or an ether or ester of glucose;

(7) a hydroxyamide having the formula ##STR20## wherein R.sub.4 represents alkyl or alkenyl having 7 to 21 carbon atoms,

R.sub.5 represents a saturated or unsaturated hydrocarbon having 7 to 31 carbon atoms,

COA represents a member selected from the group consisting of ##STR21## wherein B is an alkyl radical derived from a mono- or polyhydroxylated, primary or secondary amine; and R.sub.6 represents hydrogen or methyl, and (ii) --COOZ wherein Zrepresents a polyol residue having 3 to 7 carbon atoms;

(8) a natural or synthetic ceramide;

(9) an oxyethylenated fatty amine or a dihydroxyalkylamine; and

(10) a glycerol derivative having the formula ##STR22## wherein R.sub.7 represents linear C.sub.14 -C.sub.18 alkyl or a --CH.sub.2 A group wherein A is --OR.sub.14, R.sub.14 representing linear C.sub.10 -C.sub.18 alkyl and n represents a meanstatistical value greater than 1 and at most equal to 3 and when R.sub.7 =--CH.sub.2 A, n can also represent a true, non-statistical value equal to 2.

4. The composition of claim 1 wherein the lipid of said vesicles is an ionic amphiphilic lipid selected from the group consisting of

(1) an anionic amphiphilic lipid selected from the group consisting of a natural phospholipid, a chemically or enzymatically modified phospholipid, a synthetic phospholipid, a compound having the formula ##STR23## wherein R.sub.8 represents alkylor alkenyl having 7 to 21 carbon atoms,

(2) an anionic compound selected from the group consisting of a phosphoric ester of a fatty alcohol, heptylnonylbenzenesulfonic acid, cholesterol acid sulfate or an alkaline salt thereof, cholesterol acid phosphate or an alkaline salt thereof, alysolecithin; an alkyl sulfate and a ganglioside; and

(3) a cationic amphiphilic lipid selected from the group consisting of a quaternary ammonium derived compound having the formula ##STR24## wherein R.sub.10 and R.sub.11, each independently, represent C.sub.12 -C.sub.20 alkyl and

a long chain amino alcohol ester or a salt thereof or a quaternary ammonium derivative thereof.

5. The composition of claim 1 wherein said aqueous dispersion phase is selected from the group consisting of water, a mixture of water and a C.sub.1 -C.sub.7 alcohol, a mixture of water and a C.sub.1 -C.sub.5 alkyl polyol, and mixtures thereof.

6. The composition of claim 1 wherein said lipid vesicles are present in an amount ranging from 0.01 to 50 percent by weight based on the total weight of said dispersion.

7. The composition of claim 1 where in said lipid phase said ionic amphiphilic lipid (a) or said nonionic amphiphilic lipid (b) or a mixture thereof is present in an amount ranging from 10 to 95 percent by weight relative to the total weight ofsaid lipid phase.

8. The composition of claim 1 where in said lipid phase said ionic amphiphilic lipid (a) or said nonionic amphiphilic lipid (b) or a mixture thereof is present in an amount ranging from 40 to 90 percent by weight relative to the total weight ofsaid lipid phase.

9. The composition of claim 1 wherein said lipid vesicles have a size ranging from 20 to 3000 nm.

10. The composition of claim 1 wherein said lipid vesicles have a size ranging from 20 to 500 nm.

11. The composition of claim 1 containing an active principle having cosmetic action, an active principle having pharmaceutic action, or a mixture thereof.

12. The composition of claim 1 wherein said lipid phase of said lipid vesicles contains at least one cosmetically active liposoluble compound or pharmaceutically active liposoluble compound, or a mixture thereof.

13. The composition of claim 1 wherein said aqueous phase encapsulated in said lipid vesicles contains at least one cosmetically active water-soluble compound, or a pharmaceutically active water-soluble compound, or a mixture thereof.

14. The composition of claim 1 wherein said aqueous dispersion phase contains at least one cosmetically active water-soluble compound or a pharmaceutically active water-soluble compound, or a mixture thereof.

15. The composition of claim 1 which includes at least one formulation additive to provide said composition in a gel or lotion form.

Description:

The present invention relates to a cosmetic and/orpharmaceutical composition containing a transparent dispersion of ionic and/or nonionic amphiphilic lipid vesicles, to a process for the preparation of said dispersion and to a new dispersion used in the said composition.

It is known that it is possible to prepare vesicles from certain amphiphilic lipids, that is to say from molecules consisting of a lipophilic part and of a hydrophilic part. The vesicles obtained are delimited by a lipid phase membrane formedfrom a sheet or a number of concentric sheets, the said membrane defining a closed internal volume where a phase, known as encapsulated phase, is encapsulated. The vesicles are generally prepared in the form of a dispersion in an aqueous phase, known asthe dispersion phase. The amphiphilic lipids can be ionic lipids such as natural lecithins (egg lecithin, soya lecithin) or synthetic lecithins (dipalmitoyllecithin, hydrogenated egg lecithin). The amphiphilic lipids can also be nonionic lipids such aslinear or branched polyglycerol derivatives, linear or branched polyglycerol ethers, polyoxyethylenated fatty alcohols, polyoxyl-ethylenated sterols, polyol ethers, oxyethylenated or nonoxyethylenated polyol esters, glycol lipids, certain hydroxyamidesand others.

The lipid phase can contain one or a number of ionic amphiphilic lipids, one or a number of nonionic amphiphilic lipids or, at the same time, at least one ionic amphiphilic lipid and at least one nonionic amphiphilic lipid.

It is known to introduce into the lipid phase at least one lipophilic cosmetically and/or pharmaceutically active principle, the nature and the amount of the reactants introduced being chosen so as not to damage the stability of the vesicles. Itis also possible, in a known way, to introduce hydrophilic active principles into the encapsulated aqueous phase and/or into the aqueous dispersion phase.

For reasons of presentation, the search is to prepare dispersions of vesicles which are substantially transparent, because the cosmetic compositions prepared from transparent dispersions have a more pleasant and more attractive appearance for theuser.

The transparency (or, conversely, the opaqueness) of a dispersion, with respect to natural light, is essentially a function of the refractive index of the dispersion medium and of that of the dispersion particles, of the concentration, of themean size and of the size homogeneity of these particles. It is especially possible to increase the transparency of a dispersion by reducing the difference between the refractive index of the dispersed particles and that of the dispersion medium and/orby reducing the concentration and/or the size of the dispersed particles. Of course, it is possible to improve the transparency of a dispersion of lipid vesicles by diluting this dispersion but the concentration of active principles in the dispersionwould thus be reduced, which generally has to be avoided. It has also been attempted to reduce the mean size of the vesicles, but it is then necessary to use, for an excessively long time, during the preparation of the vesicles, powerful mechanicalmeans such as pressure homogenizers or ultrasound, which leads to a higher cost price. It was also considered to reduce the polydispersity by using grading methods such as pressure filtration or size fractionation using chromatography columns, but thesemethods are restricting and expensive.

According to the present invention, it was found that the transparency of dispersions of vesicles in which the lipid phase contains at least one ionic amphiphilic lipid and/or at least one nonionic amphiphilic lipid is considerably improved byintroducing, into the said lipid phase, at least one polyol or one isoprenoic acid containing a phytyl chain, without it being necessary to modify the method of preparation of the vesicles. It was observed that even dispersions having a high lipidconcentration, for example a concentration greater than 5% by weight, are then substantially transparent.

The first subject of the present invention is thus a cosmetic and/or pharmaceutical composition containing at least one dispersion, in an aqueous dispersion phase, of vesicles delimited by a lipid phase membrane containing at least one ionicamphiphilic lipid and/or at least one nonionic amphiphilic lipid, the said vesicles containing an encapsulated phase, characterized in that, in at least one dispersion, the lipid phase contains at least one compound of formula ##STR2## in which formula(I): either W represents --CH.sub.2 OH, --COOM or --(CH.sub.2).sub.2 --COOM, where M represents H, an alkali metal or an alkaline-earth metal, in which case X, Y, Z and V, which are identical or different, represent a hydrogen atom or a hydroxyl radical,with the condition that, when W represents the --CH.sub.2 OH group, at least one of the radicals X, Y, Z or V represents a hydroxyl radical;

or else W represents the --CH.sub.3 group, in which case X, Y, Z and V represent H or --OH combined as shown in each line of the table below:

The compounds of formula (I), which are preferred, are phytanetriol or 3,7,11,15-tetramethyl-1,2,3-trihydroxyhexadecane, 5,9,13,17-tetramethyloctadecanoic acid or the tetrols such as 3,7,11,15-tetramethyl-1,2,3,4-tetrahydroxyhexadecane or3-hydroxymethyl-7,11,15-trimethyl-1,2,4-trihydroxyhexadecane obtained as by-products in the synthesis of phytanetriol by oxidation of phytol with hydrogen peroxide.

As explained above, the first advantage of the dispersions of the composition according to the invention is that these dispersions are transparent, even for high lipid concentrations.

Moreover, it was observed that, in the case of the preparation of certain vesicles, the introduction of at least one compound of formula (I) into the lipid phase made it possible to reduce or eliminate cholesterol, which is commonly used asconstituent lipid of the wall of the vesicles, with the aim of stabilizing the vesicles. The replacement of cholesterol by a (some) compound(s) of formula (I) is of substantial advantage because the compounds of formula (I) are very difficult tooxidize, whereas cholesterol oxidizes relatively easily giving undesirable oxidation products. Moreover, the dispersions used according to the invention are generally obtained directly with a low polydispersity index without it being necessary, duringtheir preparation, to resort to an expensive fractionation. Finally, it was observed that the topical application of certain of the dispersions makes it possible to reduce the modulus of elasticity of the stratum corneum, which is very particularlyadvantageous in cosmetics.

The compounds of formula (I) are known compounds (see, for example, "Progress in the chemistry of fats and other lipids", Volume XIV, Part 1, pages 5 to 44, Ak Lough, Editor Ralph T. Holman, Pergamon Press). It is known, by an article by Yue etal. (Biochimica et Biophysica Acta, Vol. 1047, No. 1, pages 1-102), to prepare a dispersion of vesicles from a lipid phase containing phospholipids, in particular dipalmitoylphosphatidylcholine, and phytanic acid in order to study the influence ofphytanic acid on the phospholipid layer, by nuclear magnetic resonance. This study shows that the presence of phytanic acid in the vesicle membrane causes a reorientation of the phospholipid layers in the magnetic field. According to an article by R.J. Cushley et al. (Can. J. of Chemistry, Vol. 55, 1977, pages 220-226), the introduction of phytanic acid into the lipid phase of lecithin vesicles would greatly destabilize the structure of the vesicle membrane. It has also been proposed to usephytanetriol in cosmetics (see CH-A 399,655, JP-A 63/5050 and JP-A 86/236,737).

However, until the present, the use of a vesicle dispersion containing compounds of formula I in cosmetic and/or pharmaceutical compositions has never been proposed and nothing could suggest to a person skilled in the art the specific advantagesof such a use, in particular that the dispersions obtained would be transparent.

In the lipid phase constituting the membrane of the vesicles, the compounds of formula (I) represent, by weight, from 5 to 90%, and preferably from 10 to 60%, of the lipid phase. For amounts below 5%, there is no significant improvement in thetransparency. For amounts greater than 90%, the vesicles obtained are no longer stable enough.

The constituent lipid phase of the membranes of the vesicles of the dispersion according to the invention can comprise, in a known way, at least one lipid chosen from the group formed by:

A) the nonionic lipids defined below:

(1) the linear or branched glycerol derivatives of formula ##STR3## in which formula (II):

is represented by the following structures taken as mixtures or separately: ##STR4## n is a mean statistical value between 1 and 6 or else n=1 or 2 and then --C.sub.3 H.sub.5 (OH)O-- is represented by the structure --CH.sub.2 CHOH--CH.sub.2 O--;

R.sub.0 represents:

(a) a saturated or unsaturated, linear or branched, aliphatic chain containing from 12 to 30 carbon atoms; or hydrocarbon radicals from lanolin alcohols; or the residues of long-chain alpha-diols;

(b) a residue R.sub.1 CO, where R.sub.1 is a linear or branched, C.sub.11 -C.sub.29 aliphatic radical;

(c) a residue ##STR5## where: R.sub.2 can take the meaning (a) or (b) given for R.sub.0 ;

--OC.sub.2 H.sub.3 (R.sub.3)-- is represented by the following structures, taken as a mixture or separately: ##STR6## where R.sub.3 takes the meaning (a) given for R.sub.0 ;

a residue ##STR8## where: B is an alkyl radical derived from mono- or polyhydroxylated, primary or secondary amines; and

R.sub.6 denotes a hydrogen atom or a methyl, ethyl or hydroxyethyl radical; and a residue --COOZ, where Z represents the residue of a C.sub.3 -C.sub.7 polyol.

(8) the natural or synthetic ceramides;

(9) the oxyethylenated fatty amines or dihydroxyalkylamines;

(10) the glycerol derivatives described in Patent Application PCT No. 91/00889 filed on 13 Nov. 1991 and corresponding to the formula: ##STR9## in which formula (IV) R.sub.7 represents a linear C.sub.14 to C.sub.18 alkyl radical or a group--CH.sub.2 A in which A is --OR.sub.14, R.sub.14 representing a linear C.sub.10 -C.sub.18 alkyl radical and, preferably, a linear C.sub.16 alkyl radical, and n represents a mean statistical value greater than 1 and at most equal to 3 and, additionally,when R.sub.7 =--CH.sub.2 A, n can also represent a true value (non-statistical) equal to 2.

anionic compounds, such as those described in French Patent No. 2,588,256 and represented by the formula ##STR10## in which formula (V): R.sub.8 represents a C.sub.7 -C.sub.21 alkyl or alkenyl radical,

(2) anionic compounds, such as the phosphoric esters of fatty alcohols, for example dicetyl phosphate and dimyristyl phosphate in the form of acids or of alkaline salts; heptylnonylbenzenesulfonic acid; cholesterol acid sulfate and its alkalinesalts and cholesterol acid phosphate and its alkaline salts; lysolecithins; alkyl sulfates, for example sodium cetyl sulfate; gangliosides;

(3) the cationic amphiphilic lipids, such as:

the quaternary ammonium derived cationic compounds corresponding to the formula: ##STR11## with R.sub.10 and R.sub.11, which are identical or different, representing C.sub.12 -C.sub.20 alkyl radicals and R.sub.12 and R.sub.13, which are identicalor different, C.sub.1 -C.sub.4 alkyl radicals;

the long-chain amines and their quaternary ammonium derivatives, and the long-chain amino alcohol esters and their salts and quaternary ammonium derivatives;

polymerizable lipids, such as those described by Ringsdorf and others in "Angewandte Chemie", Vol. 27, No. 1, January 1988, pages 129 and 137.

The amphiphilic lipids used together represent preferably from 10 to 95%, more particularly from 40 to 90%, of the total weight of the vesicular lipid phase.

Non-lipid additives such as certain polymers, such as, for example, polypeptides and proteins, can be added to the lipid phase constituting the wall of the vesicles.

The aqueous dispersion phase according to the invention can consist of water, or a mixture of water and at least one water-miscible solvent such as C.sub.1 -C.sub.7 alcohols and C.sub.1 -C.sub.5 alkyl polyols. The aqueous dispersion phase canalso contain compounds in solution, such as sugars, organic or inorganic salts or polymers insofar as they do not modify or only slightly modify the transparency of the dispersion.

The total lipid phase concentration in the dispersion is between 0.01% and 50% by weight, preferably between 1% and 20% by weight, with respect to the total weight of the dispersion. The dispersed vesicles have sizes between 20 and 3000 nm,preferably between 20 and 500 nm.

The compositions according to the invention can be used even in the absence of any active principle, as cosmetic products for skin treatment. It has especially been observed that, when the compound of formula (I) is phytanetriol, topicalapplication of the composition makes it possible to reduce the modulus of elasticity of the stratum corneum.

However, the compositions according to the invention can also contain at least one active principle having cosmetic and/or pharmaceutical action.

In a known way, it is possible to introduce into the lipid phase of the vesicles of the dispersion at least one cosmetically and/or pharmaceutically active liposoluble compound. According to the invention, it is possible to use any liposolubleactive principle insofar as it is compatible with the compounds of formula (I) used and insofar as it does not modify in a harmful way the transparency of the compositions. Among the latter, there may be mentioned as non-limiting examples: retinoicacid, lipoprotides and steroids.

The phase encapsulated in the vesicles is generally an aqueous phase. In a known way, water-soluble active principles can be introduced into the encapsulated phase and/or into the dispersion phase. Very many compounds of this type have beenmentioned in the literature. Among the latter, there may be mentioned as non-limiting examples: glycerol, sorbitol, erythrulose and antibiotics.

Amphiphilic active principles can also be distributed between the encapsulated and/or dispersion aqueous phase and the lipid phase of the vesicles.

A list of the active principles which can be used in the compositions according to the invention is given in Table I below:

The dispersions contained in the compostions according to the invention can be prepared by any known method of preparation for the preparation of amphiphilic lipid vesicles. Various modes of preparation are, for example, described in "Lesliposomes en biologie cellulaire et pharmacologie" [Liposomes in cell biology and pharmacology], INSERM Publications/John Libbey Emotext, 1987, pages 6 to 18.

The vesicle dispersions according to the invention are preferably prepared by theprocess described below:

in a first stage, the lipid phase is prepared before forming the vesicle membrane by dissolving amphiphilic lipid(s), compounds of formula (I) and, optionally, one (or a number of) liposoluble pharmaceutically and/or cosmetically activecompound(s) in a solvent and the solvent is evaporated under reduced pressure;

in a second stage, the aqueous dispersion phase is added and the mixture is homogenized mechanically by shaking and/or ultrasound, to produce the vesicle dispersion.

Homogenization is carried out at a temperature between 10.degree. C. and 120.degree. C., preferably between 30.degree. and 80.degree. C.

The compositions according to the invention can be provided in the form of gels, lotions or serums by adding, in a known way, formulation additives which have neither their own cosmetic activity nor their own dermo-pharmaceutical activity to theaqueous dispersion phase. Among these additives, there may be mentioned gelling agents, polymers, preserving agents, dyes and fragrances.

Another subject of the present invention is certain vesicle dispersions used in the compositions, according to the invention, which are novel. Consequently, a subject of the present invention is the dispersions, in an aqueous dispersion phase,of vesicles delimited by a lipid phase membrane containing at least one ionic amphiphilic lipid and/or at least one nonionic amphiphilic lipid, the said vesicles containing an encapsulated phase, characterized in that the lipid phase contains at leastone compound of formula: ##STR12## in which formula (I): either W represents --CH.sub.2 OH, --COOM or --(CH.sub.2).sub.2 --COOM, where M represents H, an alkali metal or an alkaline-earth metal, in which case X, Y, Z and V, which are identical ordifferent, represent a hydrogen atom or a hydroxyl radical, with the condition that, when W represents --CH.sub.2 OH or COOM, at least one of the radicals X, Y, Z or V represents a hydroxyl radical;

or else W represents a --CH.sub.3 group, in which case X, Y, Z and V represent H or --OH combined as shown in each line of the table below:

A more detailed description of these transparent dispersions, which are used for the manufacture of cosmetic and/or pharmaceutical compositions, has been given above.

In order to make the subject of the invention better understood, several embodiments will now be described by way of purely illustrative and non-limiting examples.

In the examples given below, the dispersions were prepared in the following way:

1.5 g of lipid phase having the composition given in Table II below are introduced into a 100 ml round-bottomed flask and solubilization is carried out in the solvent shown in the said table. The solvent is then evaporated at 40.degree. C.through successive stages from ambient pressure to approximately 500 Pa using a rotary evaporator.

28.5 g of a 0.02% by weight sodium azide (NaN.sub.3) solution in water are added to the lipid phase film obtained during the time and at the temperature given in Table II below.

The mixture obtained is agitated using an oscillating arm shaker marketed by the company "Prolabo" under the name "Oscill 12".

The dispersion obtained, brought to a temperature of 30.degree. C., is then treated for 2 min using an ultrasound homogenizer marketed by the company "Branson Sonic Power Co" under the name "Sonifier B 30" with the following setting:

working cycle: 50%

power setting: position 5.

The following measures were carried out on the dispersion obtained:

particle size, with the apparatus marketed by the company "Coulter Electronics" under the name "Coulter N4", which operates on the quasi-elastic light scattering principle. The particle size of the vesicles is characterized by a mean diameter(d) in nanometers and a size polydispersity factor (Q). These two parameters are calculated by the method of cumulants. The measurements are carried out on dilutions containing approximately 0.3% by weight of vesicle dispersion.

The optical density of the dispersions, using a UV/visible spectrophotometer marketed by the company "Beckman" under the name "U.V. 5230", the measurement being carried out at 450 nm in a cell with a thickness of 0.2 cm after dilution of thedispersion to a quarter using a 0.02% by weight solution of sodium azide in water. The lower the optical density OD.sub.450 obtained, the greater the transparency of the dispersion.

Comparative tests were carried out in the absence of compound of formula (I) in the lipid phase and in the presence of 1,2-hexadecanediol, which is an unbranched polyol having the same chain length as the compounds of formula (I).